Propeller for airplanes and the like



June 24, 1930, I 's. E. SI ONIMSKY 1,767,776

PROPELLER FOR AIRPLANES AND THE LIKE Filed Dec. 24, 1928 Patented June 24, 1930 PATENT OFFEQE SAMUEL E. SLONIMSKY, F SAWTELLE, CALIFORNIA PROPELLER FOR AIRPLANES AND THE LIKE Application filed December 24, 1928. Serial No. 328,215.

This invention relates to propellers, and

, the main object is to provide an improved,

simple, economical, and effective type of propeller especially adapted for use on airplanes and other machines, and another object is to provide novel and effective means for detachably supporting the blades of a propeller in operative position.

Still another object is to provide a propeller having blades separable from the hub and so arranged that one or more blades may be quickly detached from and attached to the hub in selected positions.

Still another object isto provide means for increasing or decreasing the number of blalples in a propeller without changing the hu Other and more detailed objects of invention may appear as the description progresses.

In the accompanying drawing I have shown the preferred embodiment of my invention, in which Fig. 1 is a rear end view of a two-blade propeller with the blades broken away.

Fig. 2 is an enlarged sectional elevation of the same on line 22 of Fig. 1.

Fig. 3 is a transverse section of the same on line 3-3 of Fig. 2.

Fig. 4: is a transverse section of a blade on line l4 of Fig. 2.

Fig. 5 is a perspective view of the hub.

In the drawings, 1 represents a shaft on which the propeller is adapted tobe mounted, and 2 represents a hub such as is shown in Fig. 5, which is adapted to be fixed to and for rotation with the shaft 1 by means of a key 3 which seats in ways 4 and 5 respectively of the shaft 1 and hub 2, said hub being bored at 6 to receive the shaft 1.

Preferably, but not necessarily, the hub has a pair of spaced sections 7 and 8 which are provided with grooves 9, 9 etc, longitudinally alined and paralleling the axis of the shaft 1. Alternating with the grooves are portions 10, 10 etc., and at one end, preferably the inner end, of the hub I provide an enlarged flange 11 which has an outwardly turned rim 12.

The rim 12 encircles the inner portions of the grooves 9 and portions 10, as-shown in Fig. 2. The inner periphery 13 of the rim 12 is spaced from the outer periphery of the hub 2 and is tapered, for the purpose hereinafter described.

Blades 14:, 14 are provided with straight F portions 15, 15 at their inner ends which are tapered to conform to the cross section of the grooves 9, 9 etc., and are adapted to seat therein as shown. The blades 14; are notched at 16 and 17 on opposite sides thereof re-' spectively outwardly of the inner ends 15 thereof so as to provide projections 18 and 19 on the inner ends of the blades for engagement with the flange 2 and a keeper 20 adapted to be attached to the outer end of shaft 1. It will be noted that the keeper 20 is internally threaded at 21 so as to screw onto an externally threaded extension 22 on the outer end of shaft 1. Also, said keeper has an annular rim 23 which is tapered at 24: on its inner periphery to correspond to the taper of the flange 2 of the hub. The

outer edges 25 of the portions 18 and 19 of the blades are also tapered to correspond to the taper of the members 2 and 20. Thus, when the blades are positioned in selected grooves 9 of the hub with the portions 19 engaging the inner periphery of the member 2, the keeper 20 may be screwed onto the end of the shaft so as to frictionally engage the portions 18 in a corresponding manner. Due to this structural arrangement, the blades 14 may be deta'chably and rigidly held in selected positions on the hub. When the keeper has been made tight on the shaft it may be so held by means of one or more cotter pins 26, or otherwise. It will be readily observed from the foregoing description and the consideration of the drawing, that the number of blades may be increased or decreased, and the position of the blades changed on the hub by removing the keeper 20 from the shaft 1 so as to render the blades detachable from the hub and thereafter re-positioning the blades in selected grooves 9 and replacing the keeper.

What I claim is: 1. A propeller comprising a driving shaft, a hub fixed thereto and provided with a tightened on said shaft.

flange having an inturned annular rim at one end, said shaft having a threaded extension at its end, a plurality of longitudinal grooves being formed in the periphery of said hub, propeller blades having inner portions mounted in certain of said grooves, and a keeper threaded on the extension of said shaft and having an inwardly turned annular rim thereon corresponding to the rim on said hub, said blades having lateral recesses for receiving said rims.

2. A propeller comprising a driving shaft, a hub fixed thereto and provided with a flange having an inturned annular rim at one end, said shaft having a threaded extension at its end, plurality of longitudinal grooves being formed in the periphery of said hub, propeller blaoes having inner portions mounted in certain of said grooves, a keeper threaded on the extension of said shaft and having an inwardly turned annular rim thereon corresponding to the rim onsaid hub, said blades having lateral recesses for receiving said rims, and means for locking said keeper in blade supporting position.

3. A propeller comprising a shaft having a reduced threaded extension at one end, a hub having an elongated body fixed to said shaft and provided With an integral flange at one end, said flangehaving' an inwardly turned annular rinnthe body of said hub having peripheral grooves thereon, a plurality of blades seated. in said grooves, a keeperthreaded on the said shaft extension and having an annular inwardly turned rim, said blades having lateral recesses for receiving said rims whereby when said keeper is screwed tightly on said shaft the blades Will be operatively supported in said grooves and between said flange and said keeper.

A. A propeller comprising a shaft having a reduced threaded extension at one end, a hub having an elongated body fixed to. said shaft and provided With an integral flange at one end, said flange having an inwardly turned annular rim, the body of said hub having peripheral grooves thereon, a plurality of blades seated in said grooves, a keeper threaded on the said shaft extension and having an annular inwardly turned rim, said blades having lateral recesses for receiving said rims whereby when the said keeper is screwed tightly on said shaft the blades will be operatively supported in said grooves and between said flange and said keeper, the inner peripheries of said rims and the corresponding edges of the recesses in said blades being beveled for forcing the blades into said grooves when the keeper is SAMUEL n. SLONIMSKY. 

